The ordinary refrigerator is utilized to store various foodstuffs in either a frozen or a refrigerated condition to extend the freshness of the foodstuffs for a long period of time. Such a refrigerator is comprised of two cooling sections, one of which is a direct cooling type, that is, the evaporator used in a refrigerating cycle is installed in a food storage space and the effect of a direct heat-exchange is achieved. The other type of cooling section is the indirect cooling type, that is, an evaporator is mounted in an air passage remotely of the food storage space; the air is heat-exchanged by the evaporator and then the heat-exchanged air is directed to the food storage space by a fan.
The above refrigerator normally consists of a freezing compartment and a refrigerating compartment located below the freezing compartment. Further, the refrigerating section is provided with a separate space with a temperature different from that of the main refrigerating compartment, and it is called a "vegetable storage area" or a "chilled compartment" for storing meats etc. In these spaces, the foodstuffs can be individually stored in accordance with the desired conditions. On the front face of both the freezing compartment and the refrigerating compartment a door is installed on hinges on one vertical side shaft of the door so that foodstuffs can be placed in or removed from the compartment.
In the above described conventional refrigerator, the space for separately storing foodstuffs is restricted to only the freezing compartment and the refrigerating compartment. The space is so small that the desire of the user, following the current trend for foodstuffs which are stored in a fresh condition, can not be satisfied. To solve this problem, the refrigerator having a large number of separate compartment has recently been developed.
The refrigerator is used for increasing the storage space in order to allow foodstuffs to be stored in accordance with the temperature range corresponding to the individual characteristic of the particular foodstuff, and for making the operation of the door convenient. The typical conventional refrigerator having a separate compartment is disclosed in U.S. Pat. No. 3,638,717. The refrigerator has an advantage resulting from the increase in the storage volume and the convenience of the door operation. However, a problem occurs when various types of fermented foodstuffs e.g. kimchi are stored together with other foodstuffs in the same space.
Kimchi is a mixed vegetable dish made of picked vegetables combined with various seasonings. Kimchi is usually stored in a container and is fermented at room temperature to fully develop the taste of kimchi. The cured kimchi is then stored in a refrigerator. Since kimchi is usually made in a voluminous and heavy amount, a large storage space is required. As foodstuffs stored alongside the kimchi container are taken in or out of the refrigerator, they are disturbed by the kimchi container. Particularly, as kimchi is being fermented, kimchi produces a unique odor which is then contained in the cool air which is circulated in the compartment. There is a problem in that the odor often adversely affects other foodstuffs.
Further, when the door is opened so as to put in or take out foodstuffs, the odor is discharged from the compartment, thereby causing the user displeasure. Also, relatively large door must be opened to remove the relatively small amounts of foodstuff and thus a great deal cool air is discharged so that the efficiency of the refrigerator is reduced.
To resolve the above defect, the typical refrigerator having a separate compartment is disclosed in U.S. Pat. No. 5,228,499. In the refrigerator, the separate compartment is located between the freezing compartment and the refrigerating compartment. A heater and a fan are mounted in the separate compartment to ferment foodstuffs placed there. When the foodstuffs must be stored, cool air is generated by an evaporator which is located between the freezing compartment and the separate compartment, and the air is directed into the separate compartment by means of a damper.
However, there is still a problem in that the interior volume of the separate compartment is reduced because the separate compartment contains the fan and the heater therein. Another problem is that since the heater is located in a restricted place, a variation exists between the temperature range adjacent to the heater and that away from the heater. This variation causes an uneven temperature distribution in the separate compartment.
Further, the separate compartment with the, highest temperature has one side placed adjacent to the freezing compartment having the lowest temperature. The refrigerating compartment, which has a temperature lower than the temperature of the separate compartment and higher than the temperature of the freezing compartment, is located at the opposite side of the separate compartment. Such an arrangement of compartments causes a problem in that the efficiency of the heat transfer among compartments is increased and the efficiency of the storage of foodstuffs is decreased.